Constitutive and Aging Behavior of Sn3.0Ag0.5Cu Solder Alloy

• Published in: IEEE transactions on electronics packaging manufacturing Vol. 32; no. 4; pp. 221 - 232
• Main Authors: Mysore, K., Subbarayan, G., Gupta, V., Ron Zhang
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aging; Alloying additive; Alloys; Anand model; Applied sciences; Behavior; Capacitive sensors; Consistency; Constitutive relationships; Creep; Creep (materials); Design. Technologies. Operation analysis. Testing; Electronics; Equations; Exact sciences and technology; Grain boundaries; Integrated circuits; Kinematics; lead-free solders; Mathematical models; Metallurgy; Microstructure; Power law; power-law model; primary creep; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solders; Strain rate; Stress; Temperature; Testing; time-hardening creep model; Creep; Ageing; Solder metal; primary creep; power-law model; Integrated circuit bonding; Hardening; lead-free solders; Lead free soldering; Aging; Distance measurement; Power law; Comparative study; Anand model; time-hardening creep model; Strain rate
• ISSN: 1521-334X; 1558-0822
• DOI: 10.1109/TEPM.2009.2024119

We describe double-lap shear experiments on Sn3.0Ag0.5Cu solder alloy, from which fits to Anand's viscoplastic constitutive model, power-law creep model, and to time-hardening primary-secondary creep model are derived. Results of monotonic tests for strain rates ranging from 4.02E-6 to 2.40E-3 s -1 , and creep response at stress levels ranging from 19.5 to 45.6 MPa are reported. Both types of tests were conducted at temperatures of 25degC, 75degC , and 125degC. Following an earlier study where Anand model and time hardening creep parameters for Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys were reported, here we report power law model parameters so as to enable a comparison between all three alloys. Primary creep in Sn3.0Ag0.5Cu solder alloy is shown to be significant and are considered in addition to secondary creep and monotonic behavior. Aging influence on behavior is also shown to be significant. On the basis of experimental data, the following four aspects are discussed: 1) difference between testing on bulk versus joint specimen; 2) consistency between the creep and monotonic behaviors; 3) comparison against behaviors of Sn1.0Ag0.5Cu and Sn3.8Ag0.7Cu alloys as well as aganist Sn40Pb, 62Sn36Pb2Ag and 96.5Sn3.5Ag alloys; and 4) comparison of Sn3.0Ag0.5Cu and Sn3.8Ag0.7Cu relative to their aging response.